Combined air-governor and expression device.



W F. BAYER.

COMBINED AIE GOVERNOR AND EXPRESSION DEVIOE.

APPLICATION FILED SEPT. 27, 1909x Patented June 14,1910.

ANDREW e GRAHAM co. mmm-I nmcmunezus` wnsumnwn. n. eA

-UNITED STATES P ALIENT OFFICE.

WILLIAM F. BAYER, OF BUFFALO, NEW YORK.

COMBINED AIR-GOVERNOR AND EXPRESSION DEVICE.

To all 'whom it may concern:

Be it known that I, IVILLIAM F. BAYER, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented a new and useful Improvement in Combined Air-Governors and Expression Devices, of which the following is a specification.

This invention relates to the air governors employed in pneumatic musical instruments for maintaining a practically uniform air tension in the wind chest, and more particularly to governors of this kind which are combined with an expression device for accenting some of the notes of a composition. In devices of this character, as hitherto constructed, the governor-bellows has a tendency to flutter when the accent-valve is opened, producing a disagreeable noise.

The object of my invention is the provision of an eflicient governor and expression device which overcomes this objection.

In the accompanying drawings: Figure 1 is a fragmentary front elevation of an automatic piano provided with the improvement, a part of the case being removed. Fig. 2 is a transverse section, on an enlarged scale, of the wind chest, the main bellows and the air governor and expression device, the plane of the section being in line 2 2, Fig. 4. Fig. 3 is a similar section in line 8 3, Fig. Ll. Fig. el is an enlarged rear or inside view of the governor and expression device. Fig. 5 is a front view thereof with the cover removed. Fig. 6 is a horizontal section on line 6-6, Fig. t.

Similar letters of reference indicate corresponding parts throughout the several views.

A indicates the main suction bellows of an automatic piano or similar instrument which is actuated by the usual pedals B.

C indicates the stationary air reservoir carrying the main bellows A and divided by a partition c into separate upper and lower chambers c1, c2, the bellows being connected with the lower reservoir chamber c2 by a port c5.

D indicates the wind chest which connects with the upper reservoir-chamber c1 by a passage cl, as shown by dotted lines in Fig. 2.

Applied to the front side of the air reservoir is the improved air governor and expression device which consists of a box or case containing an inlet chamber E which .communicates with the upper reservoir- Specicaton of Letters Patent.

Application led September 2?, 1909.

Patented June 14, 1910.

Serial No. 519,732.

chamber c1 by a port e; an outlet chamber F which connects with the lower reservoirchamber c2 by a port f, and a connecting chamber or governor bellows Gr communieating' with the outlet chamber F by a port g, and with the upper reservoir-chamber C1 by a passage 7L, formed partly in the front wall of the governor-case, partly in a block h1 and partly in the front wall of the reservoir C, as shown in Fig. 2. As shown in Figs. 2 and 6, this block extends from front to rear of the inlet chamber E, so that the passage 7L has no communication with said inlet chamber, but connects only with the upper reservoir-chamber c1 and the interior of the governorbellows G. The lower port g is formed partly in a partition-board I separating the inlet and outlet chambers E, F from the governor-bellows G, and partly in a block y' secured to the outer side of said partition.

The front or movable wall g1 of the govvernor-bellows Gr constitutes a valve which is adapted to seat against or approach more or less closely to a raised face jl surrounding the passage in the block j for equalizing the air tension in the wind chest, as hereinafter more fully described. In its preferred form, the portion of the governor bellows which seats against said block consists of a removable plate or cover having a facing of leather or other suitable material. The governor-b-ellows is provided with a suitable expansion spring 7c which resists the inward or collapsing movement of its movable board in a well known manner.

Z indicates a sliding or other suitable valve applied to the port for cutting off communication between the lower reservoirchamber c2 and the outlet chamber F during the rewinding of the perforated music sheet. This valve may be operated by any suitable means, but is preferably actuated by a hand lever Z1 arranged in front of the key-board and suitably connected with the projecting stem of the valve.

In the partition m which separates the inlet and outlet chambers E,' F is arranged an accent or expression port m1 adapted to connect said chambers and controlled by a sliding or other suitable valve m2. This accent valve may be actuated manually or automatically by any suitable means. In the preferred construction shown in the drawings, it slides upon said partition against which it is held by a spring m3 and it is operated by ahand lever M located at the front of the key board and connected with the valve-stem by rods m, m5 and an upright rock shaft m6.

The operation of the device is as follows: Vhen the instrument is at rest, the governor bellows Gr is expanded and the valve formed by its movable board is wide open. When the instrument is to play in the normal manner without the use of the accent or expression device, the cut-oif valve Z is opened and the accent valve m2 is closed. Upon now operating the main bellows A air is exhausted from the wind chest through the port (Z, upper reservoir chamber c1, port Zz, governor bellows G, port g, outlet chamber F, and port f, the governor-bellows being collapsed more or less and the port g correspondingly restricted, according to the resistance of the bellows-expanding spring 7c and the air tension produced by the main bellows. ./Vhen the tension increases, the governor-bellows restricts the air current through the port g and when the tension diminishes, the spring /c expands the governing bellows and opens said port wider, thus equalizing the air tension in the wind chest and maintaining it practically uniform regardless of variations in the quantity of wind consumed.

Zhen it is desired to accent one or more notes, or play the same louder, the expression valve m2 is opened to a greater or less extent, whereupon the main bellows will act upon the wind chest directly through the upper reservoir chamber c1, port e, inlet chamber E, accent port m1, outlet chamber l?, and the port 7", subjecting the wind-chest for the time being to more or less of the high tension in the air-reservoir C, according to the position of the accent valve, regardless of the governing or equalizing effect of the governing bellows Gr. A composition can thus be conveniently accented or shaded according to the expression-marks on the music sheet or the fancy of the performer. In rewinding the music sheet in the ordinary manner, the cutoff valve Z is closed, thus shutting` off communication between the air reservoir C and the air governor and windchest. By connecting the governor-bellows with the wind chest independently of the inlet chamber E, said bellows does not Hutter when the accent-valve is opened, as is the case when the bellows is directly connected with said inlet chamber. The last-named arrangement also produces a disagreeable resistance or sudden stoppage of the main bellows pedals, which objection is avoided by the construction herein shown and described.

claim as my invention:

l. In a device of the character described, the combination of a case having an inlet chamber and an outlet chamber separated by a partition containing an accent passage, a valve controlling said passage, a governing pneumatic connnunicating with said outlet chamber, said pneumatic having an inlet independent of and disconnected from said inlet chamber' and accent passage, and a valve-member actuated by said governing pneumatic and controlling the passage of the air therethrough.

2. In a device of the character described, the combination of a main bellows and a wind chest, a case containing an inlet chamber connected with the wind chest and an outlet chamber connected with said main bellows, said inlet and outlet chambers being separated by a partition containing an accent-passage, a valve controlling said accent-passage, a governor-bellows communicating with said outlet chamber and having a valve-member controlling the passage of the air through the governing bellows, the latter having an inlet communicating with said wind chest but disconnected from said inlet chamber and said accent-passage.

fitness my hand this 3d day of August, 1909.

VILLIAM F. BAYER.

lVitnesses C. F. GEYER 7 E. M. GRAHAM. 

